The original prompt was something like `Rarity from MLP rearing in de stijl of Piet Mondrian,` before clicking on the variations and refinements. Midjourney did not understand the concept of rearing or, in this image, that MLP mares have different facial structures from the stallions. Surprisingly enough, the computed did draw the legs close enough to correct (the only oops is the shading on the front right implying a biologically-improbably rotation)